1. Field of the Invention
The present invention generally relates to apparatus and methods for minimally invasive treatment of obesity.
2. Description of the Related Art
Obesity is a major health concern in many countries and is particularly prevalent in developed countries. Almost one-third of the adult American population is considered to be obese, while almost two-thirds of adult Americans are categorized as being obese or overweight. The number of overweight and obese Americans has continued to increase since 1960. Obesity is now an increasingly common health concern that affects many teenagers and children as well as adults.
Obesity is also a risk factor for a broad range of diseases and conditions, including diabetes, coronary artery disease, sleep apnea, gastro-esophageal reflux disease (GERD), and cancer of the breast, prostate and colon. As a result, obesity adds enormously to the costs of healthcare in the U.S. GERD is a very common condition, in which the contents of the stomach are refluxed into the esophagus. Unlike the stomach, the esophagus lacks protection from stomach acid and is prone to damage by the stomach contents. GERD is particularly common in obese individuals.
Each year, obesity causes at least 300,000 excess deaths in the U.S., and healthcare costs of American adults with obesity amount to approximately $100 billion. Furthermore, obese individuals may become victims of discrimination in employment and social settings leading to inferior lifestyle, lower socio-economic status, and possible psychological and mental health problems.
Treatment regimes for obesity have included various diets, exercise programs, and lifestyle counseling, as well as pharmaceutical compositions and surgery. Numerous surgical procedures for the treatment of obesity are known in the prior art. One surgical approach to obesity treatment is gastric bypass surgery, which leads to decreased nutrient absorption by the patient. Another approach to the treatment of obesity is the insertion of an intra-gastric balloon to mimic fullness of the stomach. A further approach is the application of a band around the stomach wall to restrict gastric volume. Yet another approach is the insertion of an intraluminal filter or valve at the gastro-esophageal junction to restrict passage of food into the stomach. Still another approach is the direct electrical stimulation of the stomach wall to decrease the normal peristaltic motility of the stomach.
The procedures outlined above have generally been of limited value, and in addition have various disadvantages. For example, insertion of an intra-gastric balloon in the stomach is invasive and may have serious side effects, e.g., by interfering with the digestion of food. Similarly, various gastric bypass procedures, in which a portion of the gastro-intestinal tract is surgically excised, have led to under-nourished or malnourished patients, and furthermore such procedures are typically highly invasive and irreversible.
Jakabsson et al. (U.S. Pat. No. 6,102,922) disclose a food intake restriction device that includes a substantially non-expansible outer wall and an expansible inner wall. Jakabsson et al. further disclose a method in which a band of the device is looped around the esophagus and stomach such that a small stomach pouch is formed by displacing an upper part of the stomach through the loop. The band is tunnelated by suturing the upper part of the stomach to the portion of the stomach situated below the band. The pouch typically greatly expands in the course of time, normally reaching up to ten times its original size after about a year.
Forsell (US 2001/0011543) discloses apparatus for controlling food flow in a patient, the apparatus including a restriction member having two separate chambers, wherein fluid is pumped from one chamber to the other chamber to change the size of a stoma opening of the restriction member.
Barrett et al. (U.S. Pat. No. 6,587,719) disclose treatment of obesity by bilateral electrical stimulation of the right and left vagal nerve at a location in the patient's thorax. Implanted bilateral nerve stimulators or, in a clinical setting external stimulator devices, provide the electrical stimulation.
As can be seen, there is a need for apparatus, systems, and methods for the safe, reliable, cost-effective, and minimally invasive treatment of obesity. There is a further need for apparatus and methods for the effective and minimally invasive treatment of GERD.